At its presentation in 1955, the Citroen DS was a sensation and a magnet for designers, philosophers, and politicians alike. No other automobile was able to combine form and technology so coherently and seemingly effortlessly. Radical in its implementation and revolutionary in terms of comfort and safety, the DS is one of the most innovative design icons of the twentieth century. In collaboration with Lars Muller Publishers, the Swiss architect Christian Sumi published the new edition of AS in DS by Alison and Peter Smithson in 2001. In this new book, he now analytically examines the characteristics of this classic vehicle, which he documents in carefully arranged picture series and with drawings by Flaminio Bertoni and the Citroen design team, such as of the body, the chassis, or the legendary hydraulics. Using image essays from advertising campaigns for the Citroen DS, Sumi critically examines its iconisation and reception, along with theories that discuss the phenomenon in both a contemporary and philosophical context.